Certain groups of facultative anaerobic microorganisms present on the surfaces of the tooth, called dental plaque, present in the form of a bio-film, are capable of metabolizing (fermenting) carbohydrates into organic acids, especially lactic acid. As a consequence, plaque-pH is lowered from 6.5-6.7 down to pH 4-5. At a pH of 6.0-6.2, the dentine of the tooth starts to degrade in a process known as “demineralization”, where calcium and phosphate ions dissolve. Below a critical pH of 5.5-5.7, the enamel demineralises. When the acidity is neutralized to normal pH of 6.5-6.7 in the oral cavity, calcium and phosphate ions in the saliva are precipitating on the tooth surfaces. At supersaturation of the ions, the degraded areas are regenerated in a “remineralization” process. If the demineralization is too advanced for a successful remineralization to be obtained, caries lesions will occur. Consequently, frequent exposure to carbohydrates, resulting in a low pH in the oral cavity, may with time cause caries lesions. It is well known that the caries risk is lower if demineralization is avoided or if remineralization is stimulated.
Oral smokeless tobacco products are used in the oral cavity in direct contact with oral mucosa, where they are allowed to deliver flavor(s) and biologically active substances. The products are used in the mouth for an extended period of time, normally between 10 and 60 minutes and sometimes even longer. Typical oral smokeless tobacco products are for example moist snuff such as snus, and chewing tobacco, hard snuff and oral dry snuff.
Oral smokeless non-tobacco snuff products are products resembling oral smokeless tobacco products and are used in the same way as oral smokeless tobacco products.
Most oral smokeless tobacco products, as well as oral smokeless non-tobacco snuff products, contain carbohydrates. Tobacco naturally contains sugars and curing of the tobacco increases the sugar content as polysaccharides are broken down to sugar (mono- and disaccharides). Oral smokeless non-tobacco snuff products are usually based on plant materials which normally contain carbohydrates, such as sugars and starch. Oral smokeless tobacco products, as well as oral smokeless non-tobacco snuff products, may also have carbohydrates added to the raw material in the manufacturing process for improving the taste and/or texture of the product.
Generally, use of oral smokeless tobacco products as well as oral non tobacco snuff products, with high carbohydrate content, either naturally or by way of additives, and/or a low pH and/or a low buffer capacity, increases the risk of demineralization of the teeth.
It is known that repeated use of oral smokeless tobacco products as well as oral smokeless non-tobacco snuff products could cause gingival retraction and exposure of the root surface of teeth, likely as a consequence of mechanical stress. Since root surfaces are not covered by enamel, such surfaces are more prone to acid attacks of the dentine. As oral smokeless tobacco products as well as oral smokeless non-tobacco snuff products are used close to the teeth surfaces, it is of importance to prevent the teeth from demineralization possible to arise as a result of bacterial fermentation of carbohydrates originating from the products themselves, or other carbohydrates present in the oral cavity, during use of the products.
Hence, there exists a need for oral smokeless tobacco products and oral smokeless non-tobacco snuff products with an improved ability to counter-act demineralization of the teeth and/or the advent of caries lesions.